How Breast Milk May Help Babies Fight Off A Deadly Infection

As Mother's Day approaches, Canadians will be celebrating the people who brought us into this world and nurtured us as we developed. Most of the adulation will be due to social graces, such as care, kindness, and those life lessons that always come in handy. But there are other reasons -- specifically molecular -- making Mom a baby's best ally.

As Mother's Day approaches, Canadians will be celebrating the people who brought us into this world and nurtured us as we developed. Most of the adulation will be due to social graces, such as care, kindness, and those life lessons that always come in handy. But there are other reasons -- specifically molecular -- making Mom a baby's best ally.

Last month, a group of American researchers revealed one of the most important practices in a child's early life, breastfeeding, may have the ability to prevent a nasty and potentially deadly infection. It's known as Streptococcus agalactiae, however, many people recognize it by its more popular name, Group B Strep or, GBS. The group's results reveal how this unique source of nutrition for infants comes with an antimicrobial punch that saves lives.

GBS has been recognized as a significant threat for infants. The bacterium usually resides on and inside anywhere from one-sixth to one-third of women. It's usually harmless to the mother. But during birth, the bacteria can enter the baby's respiratory tract. When this happens, troubles may occur.

As one might expect, when unwanted bacteria enter the lungs, problems may arise including fever, troubles with breathing, irritability, and pneumonia. But if GBS takes hold, even worse troubles may occur. Because of the fragile nature of the immune system, the bacteria may be able to get into the bloodstream, which causes sepsis, and the brain leading to meningitis. Some five percent may die as a result.

Figuring out how to deal with GBS colonization in mothers has been a rather difficult process. Screening for the bacterium has moderate value while the use of antibiotics in early pregnancy does offer some hope. But neither of these can offer the baby any help should GBS be missed or survive treatment. This is where the study comes into light.

In previous experiments, the same team had discovered certain sugars contained in breast milk, known as human milk oligosaccharides, or HMOs, had the ability to prevent bladder infections by this bacterium. They wondered if these molecules, which can be found in the blood and urine of infants, were killing the GBS. It was time to put them to the test.

The first stage was rather straightforward. They grew GBS in the lab and then added HMOs to some of the samples. As expected, there was a reduction in the rate of bacterial growth when the sugars were added. In essence, they had proven their original discovery and were ready to move on to the next stage.

This required a little more effort as the group needed to find out which sugars were responsible. They examined several different types known to exist within breast milk. The chemicals were tongue twisters with names such as Lacto-N-neohexaose, lacto-N-neooctaose, and Lacto-N-difucohexaose II. When the experiments were complete, the winning sugars ended up being Lacto-N-tetraose and Lacto-N-fucopentaose I, better known as LNT and LNFPI.

With this in place, the next step was to identify how these sugars effectively halted microbial growth. The answer came in the form of an enzyme, known as a glycotransferase. As the name implies, the protein transfers sugars (hence glyco) from one molecule to another. When HMOs were transferred inside the cell, they ended up harming the bacterium and preventing it from growing properly.

There was only one stage left. The team wanted to find out whether the addition of HMOs could help antibiotics in killing the bacteria. Sure enough, when the sugars were added, the antibiotics worked significantly better. This meant HMOs may have a therapeutic value apart from the usual breastfeeding practice.

The results offer a rather unique insight into the importance of the mother-child bond. Breastfeeding offers a child better nutrition as well as a change to improve the ability to fight off infections such as GBS. Although HMOs do not kill the bacteria outright, the effects can ensure the invasion does not become a life or death situation.

This study also reveals a possible new direction for dealing with infections. By adding HMOs to antibiotic treatments, an individual may respond better and heal quicker. This of course requires further testing and eventual clinical trials. But at the moment, the prospect of yet another weapon against antibiotic resistance is welcome news.

Perhaps most importantly, this examination of HMOs gives us one more reason to fête mothers. Although we tend to laud them for all that they consciously do, we may be able to give them greater thanks for what they do naturally. Their existence alone should be reason enough for us all to celebrate.